a(n) = n^2 * n!.

Terms

a(0) =0a(1) =1a(2) =8a(3) =54a(4) =384a(5) =3000a(6) =25920a(7) =246960a(8) =2580480a(9) =29393280a(10) =362880000a(11) =4829932800a(12) =68976230400